Mechanism for charging refuseburning furnaces



Aug-- 1, 1939- F. c. HOLBRO'OK ET'A L 2,167,653

MECHANISM FOR CHARGING REFUSE-BURNING FURNACES Fil d Feb. 21, 1955 2-Sheets-Sheet 1 INVENTORS. 5mm (1 Hmmm 31 W Q.Z v MOWIKWMQMXQ l Aug. l,1939.

F. C. HOLBROOK ET AL MECHANISM FOR CHARGING REFUSE-BURNING FURNACESFiled Feb. 21, 1935 2 Sheets-Sheet 2 A TTORNEYS.

Patented Aug. 1 1939 UNiTED STATES PATENT OFFICE MECHANISM FOR CHARGINGREFUSE- BURNING FURNACES Application February 21, 1935, Serial No. 7,510

Claims.

This invention is a novel mechanism for charging refuse-burning or otherfurnaces wherein the charges are dumped at intervals from above by adescending chute. The invention has been developed especially for thefeeding of various kinds of refuse into an incinerator furnace, but haswider commercial applicability.

Refuse is understood as including various kinds of dry refuse or waste,which is combustible, and as well garbage or other kinds of moist or wetrefuse. Furnaces or incinerators of this class are largely used formunicipal purposes, and the usual type of such furnace comprises acharging chute which delivers from a hopper by gravity into the furnacechamber, with a normally closed charging gate that supports the weightof the refuse or charge which rests above it in the hopper and chute butwhich is openable for the periodic dumping of the material into thefurnace chamber. To aid description the part of the chute which is abovethe charging gate will be hereinafter considered as part of the hopper.

The general object of the present invention is to afford a furnacecharging or refuse dumping mechanism of the class having a normallyclosed but openable charging gate, which will be efiicient andconvenient in operation and simple and durable in construction. Afurther object is to provide a gate operating mechanism requiring lowpower consumption as compared with those commonly in use. A furtherobject is to afford automatic or semi-automatic action.

Another object of the invention is to afford a charging mechanismwherein the dumping gate, which takes the accumulated weight of thecharge, is protected or shielded in an advantageous manner from thedestructive heat of the fire in the furnace below, and thus may becomposed of iron without being subject to danger of burning away. Otherobjects and advantages of the present invention will be explained in thehereinafter following description of illustrative embodiments thereof orwill be manifest to those conversant with the subject.

To the attainment of the recited objects and advantages the presentinvention consists in the novel mechanism for charging refuse-burning oranalogous furnaces, and the novel features of operation, combination,arrangement and construction herein illustrated or described.

In the accompanying drawings Figure 1 is a vertical section through acharging mechanism for a refuse-burning furnace embodying the presentinvention with certain parts seen in elevation.

Fig. 2 is an exterior elevation of the mechanism shown in Fig. 1.

Fig. 3 is a top plan view of the same taken partly in section on theline 3-3 of Fig. 1.

Fig. 4 shows the same mechanism in rear eleva- 5 tion, that is lookingtoward the right side of Figs. 1, 2 or 3.

Fig. 5 is a partial front elevation showing the driving motor andconnections.

Fig. 6 in vertical section and right hand elevation shows the chargingor feed mechanism hereof applied to a usual type of refuse-burningfurnace, or incinerator.

Fig. 7 is a view similar to Fig. 1 showing a modified form of chargingmechanism.

Fig. 8 is a view similar to Fig. 1 showing a still further modification.

Fig. 9 is a circuit diagram of the control means partly shown in Fig. 2.

Referring first to Fig. 6, in connection with Figs. 1-5, the furnacegrate I0 is shown as located below the main combustion chamber, thefront wall ll appearing at the left side of the figure. The grate isair-supplied as usual and the refuse is dried and burned on the grate,or it might be partially or wholly predried. Auxiliary fuel may beintroduced for ignition or combustion.

Above the chamber is the arch or top wall l2 having a charging openingl3 through which the refuse material is dumped into the furnace chama0ber. To the rear of the grate is shown a conventional bridge wall l4over which the gaseous products pass on their way preferably to asupplemental combustion chamber, for further combustion, and thenceperhaps to a heat utilizing apparatus or boiler, a gas washer, and astack, or other apparatuses usually employed with incinerator furnaces.

Well above the charging opening l3 of the furnace is the overhead hopperl6, supplied with refuse in any known manner. Below the hopper is avertical extension I! which contains a portion of each charge, supportedon the charging gate 2!, before dumping or feeding into the furnace.Below the hopper portion I! and gate is a widened continuation or chuteI8. These elements are preferably composed of iron; while below themextends a chute portion l9 which is exposed to tlie'heat of the furnaceand is composed preferably of refractory material, as firebrick. 50

The chute therefore delivers from above into the furnace, that is,charges downwardly by gravity to the combustion chamber, so that whenthe chute is open radiant heat may enter it, as well as the hot gases.

At the foot of the hopper portion I1 and giving support to the refusecharge in the hopper is the refuse feeding or charging gate 2!, normallyclosed but openable for dumping each charge into the furnace. It isshown as consisting preferably of a plurality of gate sections composedof iron, normally closing the chute and supporting the refuse butadapted to shift or swing downwardly, for example to the dotted linepositions shown in Fig. 1, for the delivery of each refuse charge to thefurnace.

Below the main or charging gate 2| is a shield 22, shown as consistingof a pair of shielding members or sections composed of or faced withrefractory material, such as firebrick. The shield 22 is exposed to theheat of the fire and serves to protect the iron main gate 2| from theheat. Between the gate and shield is an insulating air space or cell 23of substantial volume, and the gate and shield are spaced apartvertically sufficiently preferably to accommodate the main gates whenswung downwardly to the dotted positions shown, while the shields swingdown into the arch opening I3, as also shown in Fig. l.

The charging gate may retract or open otherwise than by swinging down.The shield may be of various refractory materials, meaning high heatresistant materials, as firebrick, or certain metal alloys, butpreferably not ordinary iron where high temperatures are involved. Theretractible shield not only cuts off radiant heat, but preferably is aclosed shield which excludes hot gases, and prevents the danger ofignition of material above the main gate.

The function of the refractory shield 22 is to protect and shield themain or iron gate 2| from the intense heat of the furnace, particularlyfrom the radiant heat when the fire is hottest, which may be destructiveof exposed iron parts. The shield is not arranged to support or deliverrefuse into the furnace, but on the contrary the operation of thisinvention is to open or retract the shield substantially simultaneouslywith the main gate, both gate and shield thus dropping to the dottedline position shown in Fig. 1, for emptying a charge into the furnace,and each then resuming its closed position shown in full lines, with aninsulating air-cell between. The upper gate merely supports and dumpsthe charge; the lower one merely shields the upper shield but retractsto clear the chute and permit the dumping,

For mounting the respective gate and shield and effecting the describedoperations the following illustrative mechanism is shown. The main gatesections 2| are shown mounted on cross shafts 25 fulcrumed in the metalwalls of the chute. Each of the cross shafts carries a rockarm 26, andthese rockarms preferably are acted upon by counterweights 2! tending tolift the gate into closed position, thereby counterbalancing to anydesired extent the weight of the gate and the charge of refuse restingthereon.

The two cross shafts 25 may be rocked in unison, for example throughvertical links 28 connecting the rockarms 26 with lower rockarms 29extending from the exterior ends of cross shafts 30. The shafts 30 maybe those which carry the shield gate sections 22 and they have theirbearings in the iron walls of the chute. The arms 26 and 29 aresubstantially parallel so that the upper gate and lower shield will openand close in unison. The entire swing of the rockarms and gate andshield may be in the neighborhood of between the open and closedpositions shown in Fig. 1.

The described mechanism is preferably operated by power, and for thispurpose an exterior end of each of the shafts 30 is provided with abevel gear 32, these bevel gears engaging bevel gears 33 on alongitudinal operating shaft 34 turning in bearings 35. It is thereforeonly necessary to rock the shaft 34 to effect the opening and closingmovements. The operating shaft 34 is provided with a rockarm 36 which,like the rockarms 23 and 28, may swing upwardly and downwardly throughabout 90 of angle, the gears 32 and 33 having the same number of teeth.A link 31 is shown as extending to the rockarm 36 from a crank pin 38provided on a disk 39 which may also constitute a gear, and the axle orshaft of which turns in a bearing 40. The portion of the disk 39 betweenthe crank pin 38 and the shaft may be considered as a crank or crankarm. The gear 39 is driven with speed reduction by a pinion 4| on theshaft of a motor 42. The gear is located, preferably below the arm 36,so that when the arm is in its extreme positions the crank is in itsdead center positions. The motor may have a built-in worm or otherreduction gear. The rockarm 36 is describable as an operating membermovable to and fro by the actuation of crank pin 38, and the term crankis intended to include an eccentric, this acting through the link orpitman 3'1.

By these arrangements, assuming the motor to turn continuously, thepinion 4| and gear 39 would turn continuously, and the various rockarms,rockshafts and gate sections would rock back and forth through 90 asdescribed. The driving motor however is to be operated to stop with thegates in closed position, holding them there until suitably restarted.Preferably also the motor will stop again with the gates fully open,until again restarted for the subsequent closing of the gates, or therestarting might be automatic after a brief timed dwell sufficient tocomplete the dumping of the refuse.

Owing to the use of the crank 38 and connecting rod 37 for effecting therocking movements the reversal of the motor is not necessary, and it maybe turned always in one direction, but in termittently as described. Agreat advantage pertains to the crank and pitman arrangement, wherebythey are in their upper dead center or alined position when the gate 2!is closed, so that the load is. effectively supported by the crank andpitman without strain or pressure on the driving connections. At bothupper and lower dead center all of the gate sections are locked inposition.

The control of gate operation may be manual, but preferably is automaticor semi-automatic, and the disclosed control means may be described asfollows. On one of the rockshafts 25 is shown a control arm 44,swingable therefore through 90 between closed and open positions of thegates. The control arm 44 cooperates with an upper switch 45 and a lowerswitch 46 serving to cause the cessation of motor drive as the gatescome to their closed and opened positions respectively, see Fig. 2.These switches therefore operate as limit switches, being so positionedas to cause cessation of action when the gates have reached the limit oftheir upward and downward movements. The switches may be of well knownconstruction, with an outstanding button or contact adapted to becontacted by the control arm 44 for causing, for example, the opening ofeach switch.

The diagram in Fig. 2 shows. line wires 49 constituting a source ofenergizing current, these leading to a circuit controller 50, adaptedfor remote control, its interior arrangements and circuits being shownin Fig. 9. It may be located at any convenient point, remote both fromthe driving motor and the control arm 44. The function of the remotecontroller '50 is to connect the line wires 49 with the circuit 5! ofthe motor when the motor is to be driven, and disconnect when the gatesreach their stopping positions.

The control operation may be initiated by a manual starting button orswitch 53 associated with the controller. Whenever the motor starts intooperation the gate mechanism is actuated and the control arm 44commences to swing either downwardly to open or upwardly to closedposition as the case may be. In Fig. 2 the arm 44 is shown as havingswung upwardly and operated to open the limit switch-45. This switch isin a local circuit which leads to the controller 59 and is so connectedtherein that the contact of the arm upon the limit switch button causesthe breaking of the connections to the motor circuit 5|, and vice versa.The result is that the mechanism stops operation with the gates closed.When the starting button 53 is now operated the resumed action of themotor causes the opening of the gates and the swinging down of thecontrol arm. This first releases the limit switch 45, so that it is inposition for the next stopping. The arm 44 finally contacts the limitswitch 46 which is connected by a circuit 56 with the controller 55,causing the energizing circuit 5i again to be broken, and the action isstopped with the gates wide open. As stated, the motor may next besuitably restarted to cause re-closing.

Fig. 9 shows a simple wiring arrangement that may be used for controlpurposes. It agrees in position with Fig. 2, the upper limit switch 45being held open against its spring and the lower switch 46 closed by itsspring. The controller 56 includes a double pole switch 58* which whenclosed connects the line wires 49 with the motor 42. It also includes asolenoid 5% which when energized lifts its core and closes the doublepole switch 5!] against an opening spring. The starting switch 53 isshown as a double acting single pole switch. Thisswitch is shown asclosed at the right, but the upper limit switch 45 is open, so that nopower is being delivered to the solenoid, which had released the doublepole switch, and

which latter had been opened by its spring, renderinginoperative themotor, with the charging and shield gates. closed. If now the startingswitch is reversed to the dotted line position the solenoid circuitbecomes closed through circuit 56, and the switch 56 is thus caused toclose. Said switch thereupon delivers current to the motor 42 whichtherefore starts rotation and causes the progressive opening of thegates. When fully open the control arm 44 Fig, 2 contacts and opens thelower limit switch 46, breaking the circuit 56, and causing the openingof switch 5!] and the stoppage of the motor. In the meanwhile the upperlimit switch has closed, in readiness for the next reversing operation.

In the modification shown in Fig. 7 the main or charging gate 2| may besimilar to that already described, but the refractory shield 66 is shownin a form adapted to retract from closed to open position by a slidingrather than a swinging motion. For this purpose each sliding section 6!!is shown provided with rollers 6! running on inner tracks 62. The trackshave a riser or upslant 63 which takes effect on the rollers as theypass from the tracks 62 to the outer tracks 54. By this arrangement asthe opposite sliding sections are moved inwardly to closed position theydrop slightly so as to become seated on the surrounding parts or rim ofthe furnace chamber adjacent to the charging opening l3.

'For the purpose of retracting the sliding shield 5 69 to open the chutewhen the main gates are swung downwardly the following connectionsareshown. On each sliding section is an upstanding plate or bar 65carrying'a pin 66 which is engaged by the slot or fork 61 formed atthe'lower end of 1 a swinging arm Gil-mounted on the carrying shaft 25of the adjacent main gate section. In this embodiment the operatingrockshaft 34" is placed substantially at the level of the shafts 25 sothat the maingates derive their opening and closing motions directlyfrom the shaft 34 through the gears 33 and 32 while the shield sectionsderive their motion from the shafts 25 through the connections 65-68described. The shield is thus caused to recede and clear the chute intime for a the delivery of the refuse from the charging gate.

In the modification shown in Fig. 8 the upper or charging gate 2-! ;maybegsimilar to that already described, but in this case thelower orshielding member 'Hlis :movable on the same mounting as the main gateand in that way is caused to open and close simultaneously with theopening and closing of the upper gate. In this embodiment each section2| of the main gate, swinging about its supporting shaft 25, is providedwith an oppo- 3 site pair of depending segment plates 1!, the lower edgeof each of which has mounted upon it a curved arrangement or system ofrefractory blocks 72 constituting the shield, the outer or lower surfacethereof being approximately cylindrical, so that when the main sectionsare swung downwardly to open position, each of the shield sectionsswings down and out, so as to clear the chute for the chargingoperation, while maintaining a substantially closed relation to therefractory lower chute portion l9 which stands up above the top wall [2of the furnace chamber. The outermost element 12 of each section of theshield 16 is provided at its outer edge with a projection or flange filwhich may serve both as 4 a stop to limit the closing movement of thecorresponding shield section and as a sealing means.

The refractory or firebrick elements 12 may be variously combined andmounted to constitute a shield which shifts or swings simultaneously 0with the opening and closing of the charging gate. As shown, each of thefirebrick members 19 is provided with an inward extension 13 perforatedor adapted to receive a system of holding rods 14 supported at theirends in the segment plates H.

In this embodiment the main gate sections 2| are shown as coming toclosed position while still somewhat inclined below the horizontal.Between the main gate sections and the refractory portions of theshielding sections are air cells or spaces 16 serving the same purposeas the air spaces 23 shown in Figs. 1 and 7, affording additional heatinsulation for the main gates. Fig. 8 shows in dotted lines the outswungpositions of 6 the charging and shielding sections. The counterweightand operating connections may be similar to those illustrated in Fig.'7.

The gates 2|, in all embodiments, swing down within the chute I 8between the right and left lateral side walls 26 of the chute,substantially in contact with them. In Figs. 1-6 and Fig. 7 the chute iscompleted by the front and rear lateral walls 20 In Fig. 8 however theWalls 20 are omitted, being unnecessary, as closure is efiected by thefit of the gates 20 and by the fit of the shields 10 with the refractoryentrance l9 to the furnace. In all cases the chute is fixed as to itsdescribed lateral walls, and is laterally closed either by the fixedwalls 20 and 20 or by the walls 20 and the cooperation of gates andshields with the walls 20 and entrance l9 as in Fig. 8.

We claim:

1. Apparatus for the periodic charging of a furnace, comprising acharging chute and delivering downwardly into the furnace chamber, afixed hopper above and in alinement with the chute, and a normally-shutcharging gate mounted in the chute and supporting the weight of thecharge in the hopper and openable by swinging downwardly for dumpingeach charge into the furnace; and means for opening the gate for eachcharging operation and thereupon closing it, comprising an electricmotor with driven connection for lowering and lifting the gate, a limitmeans having connections operated by the movement of the gate to extremeposition and adapted to render the motor inoperative, and means torestart the motor.

2. Apparatus as in claim 1 and wherein the connections operated by themovement of the gate include a swinging arm movable with the gate andthe limit means comprises a limit switch operated by the arm when thegate is completely closed thereby to stop the motor.

3. Mechanism as in claim 1 and wherein the motor is of a kind that turnsin one direction only, with crank connections to the gate, arranged sothat the crank is in dead center when the gate is shut, a circuitcontroller operating upon the circuit to the motor to open or close it,and said limit means comprising two limit switches, one operated by thefull closing and the other by the full opening of the gate, to operatethe controller to stop the motor, and a restaring means to reestablishthe circuit to the motor,

4. Mechanism for the periodic charging of a furnace, comprising acharging chute having lateral walls at two opposite sides and deliveringdownwardly through the furnace entrance, a hopper above and constitutinga continuation of the chute, and a charging gate comprising an oppositepair of sections swingingly mounted in the upper part of the chute,normally shut to receive and openable by downward swinging abouthorizontal axes for dumping each charge into the furnace; and incombination therewith a movable shield of high heat resistant materialcomprising an opposite pair of sections swingable about substantiallythe same axes as the gate sections; said shield sections being eachadapted to extend from the inner portion of the corresponding closedgate section downwardly and outwardly into closing relation to thefurnace entrance, thereby to afford a protective air cell or spacebetween the gate and shield, and to maintain the chute substantiallyclosed at the two sides that are not closed by said opposite lateralchute walls, and means for opening the gate and shield sections for eachcharging operation and thereupon closing them; the furnace havingadjacent to its entrance an upstanding extension or flange at each ofthe two sides closed by said shields, and each shield section having adownwardly extending projection or flange adapted to engage suchupstanding extension when the gate sections are shut, thereby to actboth as a stop for the closing movement and as means for producing aneffective seal at eash side.

5. Apparatus for the periodic charging of a furnace, comprising a fixedcharging chute delivering downwardly into the furnace chamber, a fixedhopper above and constituting a continuation of the chute, and anormally-shut charging gate mounted swingably in the chute to receiveand support the weight of the charge in the hopper and swingabledownwardly for dumping each charge into the furnace; and in combinationtherewith an arcuate shield of high heat resistant material below thegate in a position to afford an air cell or space between the gate 5 andshield, said shield being normally in shut position for shielding thegate from the furnace fire but mounted in the chute to swing downwardlyabout the same axis as the gate and being thereby openable with the gateto render the chute clear for delivery of charge by the gate to thefurnace, and operating mechanism for swinging downwardly about said axisboth the gate and shield for each charging operation; the furnace havingan upstanding extension closed by the shield and the shield having adownward extension adapted to engage such upstanding extension when thegate is closed, thus to seal the chute.

FRANCIS C. HOLBROOK.

JOSEPH C. ZENGERLE.

